Investigation of optimal conditions needed for the production of indigo and subsequent dyeing using CO2/O2 sensors and a cellphone camera.

An investigation of the process involved in the production of and dyeing with indigo based on a CO2/O2 sensor device and a cellphone-camera is reported. The former involves transforming indican to indigo, and the latter the process by which indigo and indigo-white are produced. During the process of indigo production, a clear and positive correlation can be observed between the concentration of gas levels (either the production of CO2 or the consumption of O2) and the final yield. The authors found that for the first time that the change in the concentration levels of CO2/O2 can be used as important parameters for indigo dyeing. The optimal time required to produce indigo can be decided by the change of CO2/O2 concentration level. It is no long should depending on the experience of a craftsperson. Furthermore, the optimal time needed to produce indigo also can be decided by the concentration levels of glucose. The color analysis of indigo dyeing can be performed by using a camera and by calculating the RGB and HSV (hue, saturation, value) values.

Comparison and characterization of pigments and dyes by Raman spectroscopy.

This review provides a general understanding of Raman spectroscopy for use in the identification of pigments and dyes. The methodologies associated with a number of different related applications are also summarized. The first part of this review clarifies our basic knowledge regarding natural minerals and pigments. The second part discusses the fundamentals of currently used Raman spectroscopy, including surface-enhanced Raman scattering, µ-Raman spectroscopy, Raman imaging and spatially offset Raman spectroscopy. The third part focuses on recent applications, including the identification and analysis of various pigments and dyes that are used in paintings and related artworks. These studies show that Raman spectroscopy has great potential for use as a method for the rapid, non-destructive identification of such substances.